Peginterferon alpha-2b plus ribavirin compared with interferon alpha-2b plus ribavirin for initial treatment of chronic hepatitis C in Saudi patients commonly infected with genotype 4.

AIM: Comparing the efficacy of peginterferon alpha-2b plus ribavirin with interferon alpha -2b plus ribavirin in Saudi patients with chronic hepatitis C virus (HCV) commonly infected with genotype 4. METHODS: A total of 96 patients with chronic HCV infection were randomly assigned to two treatment groups. Forty-eight patients received once weekly 100 microg of peginterferon alpha-2b plus ribavirin given orally 800 mg/day (peginterferon group). Another 48 patients received thrice weekly 3 million units of interferon alpha-2b plus ribavirin 800 mg/day (interferon group). At the end of treatment (48 weeks) and sustained (72 weeks) biochemical and virologic responses were determined. RESULTS: In the peginterferon group, 70.8% (34/48) patients attained both biochemical and virologic responses at the end of the treatment as against 52.1% (25/48) patients in the interferon group. (P=0.09 for both). Similarly, sustained biochemical and virologic responses in the peginterferon group were attained in 52.1% (25/48) and 43.8% (21/48) patients as against 43.8% (21/48) and 29.2% (14/48) patients in the interferon group, respectively (P=0.54 and 0.20, respectively). The sustained virologic response rates in patients with genotype 4 were 42.9% (12/28) in the peginterferon group and 32.3% (10/31) in the interferon group (P=0.43). Patients in peginterferon group had higher, although statistically not significant adverse reactions. CONCLUSIONS: Saudi patients with chronic HCV attained a higher, although statistically not significant sustained virologic response with pegylated interferon plus ribavirin compared with interferon plus ribavirin.     

IL28B polymorphisms predict response to therapy among chronic hepatitis C patients with HCV genotype 4

Summary. Genetic polymorphisms near IL28B are associated with spontaneous and treatment‐induced clearance of hepatitis C virus (HCV). Our objective was to assess the predictive value of IL28B polymorphisms in the treatment of chronic hepatitis C of patients with HCV genotypes 4, for which data are currently limited. We analysed the association of IL28B polymorphisms with the virological response to treatment among 182 naïve chronic hepatitis C patients with HCV genotype 4, all from Syria. Associations of alleles with the response patterns were evaluated by univariate analysis and multivariate logistic regression, accounting for all relevant covariates. Sustained virological response (SVR) was achieved in 26% of rs8099917 TG/GG carriers compared with 60% of TT carriers (P < 0.0001) and 35% of rs12979860 CT/TT carriers compared with 62% of CC carriers (P = 0.0011). By multivariate analysis, the association between rs8099917 and SVR remained significant (OR = 0.19, 95% CI 0.07–0.50, for TG/GG vs TT, P = 0.0007), with the only significant covariate being advanced fibrosis (OR = 0.13, 95% CI 0.04–0.37, P = 0.0002). In conclusion, IL28B polymorphisms are the strongest predictors of response to therapy among chronic hepatitis C patients with HCV genotype 4.     

Can we develop improved derivatives of valproic acid?

Valproic acid is one of the major antiepileptic drugs. In animal models, valproate showed less anticonvulsant potency than the other three established antiepileptic drugs: phenobarbital, phenytoin and carbamazepine. In addition, two major side-effects, teratogenicity and hepatotoxicity, have been associated with valproate Iherapy. Due to the above and the shortage of new antiepileptic drugs there is a substantial need to develop improved derivatives of valproate. This paper analyses three kinds of valproate derivatives: valpromide, the primary amide of valproate, and its analogues; monoester prodrugs of valproate and an active metabolite of valproate, 2-n-propyl-2-pentenoate. The comparative evaluation was carried out by pharmacokinetic and pharmacodynamic analyses in animals. From the data accumulated so far, we can conclude that 2-n-propyl-2-pentenoatc and/or a valpromide isomer, which does not undergo amide acid biotransformation and preferably is not an epoxide hydrolase inhibitor, may prove to be improved derivatives of the parent compound valproic acid.     

Paracoccidioides brasiliensis (Lutz, 1908) isolated by hemoculture in a patient with the acquired immunodeficiency syndrome (AIDS)]

A case of an AIDS patient with positive blood culture for Paracoccidiodes brasiliensis is reported. The patient was a 29-years-old male born in Nova Londrina (Paraná State, Brazil) who presented splenomegaly and fever of unknown origin. Three blood cultures were performed, each one of them for aerobic bacteria, mycobacteria and fungi. Cultures for aerobic bacteria and mycobacteria were negative. However, the yeast phase P. brasiliensis was isolated from two cultures in BHI agar, 20 days after inoculation in Negroni medium. The patient was classified in group V according to the Centers for Disease Control (CDC) criteria for AIDS, due to a Pneumocystis carinii pneumonia. Treatment was discontinued due to an individual decision of the patient on the second dose of amphotericin B. This antibiotic was replaced by ketoconazole in the daily dose of 800 mg. The patient died one year after the isolation of P. brasiliensis on blood culture.     

Pharmacokinetic Analysis and Antiepileptic Activity of N-Valproyl Derivatives of GABA and Glycine

Purpose. To explore the possibility of utilizing valproyl derivatives of GABA and glycine as new antiepileptics by using the structure pharmacokinetic-pharmacodynamic relationship (SPPR) approach. Methods. The pharmacokinetics and pharmacodynamics (anticonvulsant activity and neurotoxicity) of the following four conjugation products of valproic acid (VPA), glycine and GABA were investigated: valproyl glycine, valproyl glycinamide, valproyl GABA and valproyl gabamide. Results. Only valproyl glycinamide showed a good anticonvulsant profile in both mice and rats due to its better pharmacokinetic profile. Valproyl glycinamide was more potent than one of the major antiepileptic agents - VPA and showed a better margin between activity and neurotoxicity. Valproyl glycine and valproyl GABA were partially excreted unchanged in the urine (fe = 50% and 34%, respectively), while the urinary metabolites of the amide derivatives were valproyl glycine and valproyl GABA. Conclusions. The four investigated valproyl derivatives did not operate as chemical drug delivery systems (CDDS) of glycine or GABA, but acted rather as drugs on their own. The current study demonstrates the benefit of the SPPR approach in developing and selecting a potent antiepileptic compound in intact animals based not only on its intrinsic pharmacodynamic activity, but also on its better pharmacokinetic profile.     

Pharmacokinetic analysis and anticonvulsant activity of two polyesteric prodrugs of valproic acid

The pharmacokinetics of the following two polyesteric prodrugs of valproic acid (VPA) have been investigated: 1,4-butanediol divaiproate (BDV) and glyceryl trivalproate (GTV). In addition, the anticonvulsant activity of these compounds has been evaluated and compared to that of VPA and valpromide (VPD). Valproic acid, and its two esteric derivatives were administered intravenously to six dogs at an equivalent dose (400 mg VPA) and their pharmacokinetics investigated. In the case of BDV, the biotransformation to VPA was complete, but in the case of GTV, it was only partial. Of the two investigated esteric prodrugs of VPA, only BDV demonstrated anticonvulsant activity and showed less neurotoxicity than VPA and VPD, and therefore had a better protective index. The anticonvulsant activity is explained on pharmacokinetic and pharmacodynamic grounds due to its complete conversion to VPA and the possible synergism in anticonvulsant activity between VPA and 1,4-butanediol.     

Electrophysiological aspects of benzodiazepine antagonists, Ro 15-1788 and Ro 15-3505.

The comparative action of two specific benzodiazepine antagonists, Ro 15-1788 and Ro 15-3505 was examined in six healthy volunteers. Medication was given i.v. in a double-blind cross over pattern, and EEG was recorded throughout each experimental session. Ten minutes after the injection of one of the antagonists or placebo, midazolam was injected in incremental doses until first signs of drowsiness appeared in the EEG. The EEG was computer analyzed, using adaptive segmentation and time-dependent clustering. Continuous power profiles for various frequency bands, as well as power ratios for the physiological frequency bands (e.g. sigma/alpha power ratio) were generated. It has been found that sigma/alpha power ratio was the most sensitive parameter detecting early effects of midazolam on the EEG signal, thus enabling a semi-quantitative titration of the antagonists by midazolam. Ro 15-1788 in doses of 5 mg i.v. was counteracted on average by 7.3 mg midazolam. From the EEG analysis it has been found that Ro 15-3505 was at least 4-5 times more potent than Ro 15-1788.     

Evaluation of processing methods to equitably aliquot sputa for mycobacterial testing

We compared bacillary loads after splitting sputum specimens by chemical (N-acetyl-l-cysteine [NALC]) and mechanical homogenization by vortexing with sterile glass beads. NALC and vortexing with glass beads were equally effective at homogenizing sputum specimens, resulting in an equal distribution of tubercle bacilli in the aliquots.